Note: Descriptions are shown in the official language in which they were submitted.
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"DEV{CE AND METHOD FOR HANDLING TUBULAR KNITTED ARTICLES,
SUCH AS STOCKINGS AND SOCKS OR THE LIKE"
DESCRIPTION
Technical field
The present invention relates to methods and devices for handling tubular
knitted articles, in particular, although not exclusively, stockings and
socks.
More specifically, the present invention relates to methods and devices
which have the function of correctly orienting tubular articles picked up from
a
container in which they are placed randomly.
State of the art
To produce stockings and socks, semi-finished tubular knitted articles are
usually produced by either single or double cylinder circular knitting
machines.
The semi-finished article delivered from the circular machine has an elastic
band
at one end and an open toe at the opposite end. The open toe must be sewn or
linked to form the closed toe of the finished tubular article. In some
machines
closing of the toe is performed using devices combined with the needles of the
cylinder and/or of the dial of the machine. Nonetheless, this requires a
specifically designed knitting machine, or a modification to existing
machines.
When, on the other hand, the semi-finished articles are unloaded from the
circular machine with the toe still open, a subsequent processing operation is
required on each article, which consists of picking up the article and
inserting it
with the correct end, i.e. the end forming the open toe, into a linking or
sewing
machine. These operations to pick up the tubular articles, which have been
placed randomly in a container, and position them on a tubular transport
member
or directly in the sewing or linking machine are conventionally performed by
hand, resulting in labor costs having a high incidence on the finished
product.
Machines have also been designed to allow these operations to be
performed automatically.
For example, US-A-5040475 describes complex machinery that picks up
individual tubular articles from a container in which they have been placed
randomly. By feeding the article along a specific processing path, detection
means first detect the orientation of the tubular article along the feed path,
recognizing whether the toe or the elastic band of the article is the leading
end.
After this has been detected, the tubular article is placed in an intermediate
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station, from which it is delivered in one direction or in the opposite
direction
according to the orientation with which it entered the station.
Therefore, when exiting the intermediate station the tubular article is always
facing in the same direction (i.e. always with the toe being the leading end,
or
always with the elastic band being the leading end) to be then spread
longitudinally and inserted over a transport tube which transfers the tubular
articie towards a sewing machine. This machinery is extremely complex and not
very reliable.
JP-A-7468502 and JP-A-1272801 describe other appliances for handling
tubular articles such as stockings or socks for the purpose of suitable
orientation
thereof.
US-A-6719577 describes a device, which longitudinally orients individual
tubular articles collected from a container, in which they are placed
randomly.
EP-A-1221502 describes a device in which individual socks or other tubular
articles are picked up from a container in which they are placed randomly and
are then oriented so that they are always positioned with one of their ends
facing
forwards by means of a specific pneumatic path and using detection systems
capable of distinguishing the elastic band from the toe of the article through
different characteristics of elasticity of the fabric.
US-A-5769286 describes a spreading device for longitudinally spreading
socks or other tubular knitted articles.
EP-A-178143 describes a further system for detecting the orientation of a
tubular textile article by distinguishing between the elastic band and the
toe.
US-A-5511501 describes complex machinery, which picks up individual
tubular articles from a container in which they are placed randomly and
separates them, placing each tubular article in a respective container of a
smaller size. Subsequently, each article is picked up from the respective
smaller
container and fed to a specific pneumatic path inside which the tubular
article is
oriented so that it is delivered from the pneumatic path always with the same
orientation.
US-A-5884822 describes a further device and method for picking up
individual tubular articles from a container.
US-A-5992712 describes yet a further device for picking up individual
tubular knitted articles and orienting them appropriately.
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Similar problems regarding the orientation of tubular articles can be found
when feeding stockings or socks to a pressing machine. For example, in the
production of women's stockings, the problem exists of inserting each
stocking,
with the toe already sewn, over a pressing template and for this purpose the
individual stockings must be picked up from a container in which they are
placed
randomly to be inserted over the form. Similar problems also occur in machines
for packaging knitwear and hosiery articles, such as stockings and socks.
Objects and summary of the invention
An object of the present invention is to provide a particularly simple,
efficient and reliable device to perform orientation of tubular knitted
articles, in
particular, although not exclusively, stockings and socks, picked up from a
container in which they are placed randomly, to be subsequently fed with the
correct orientation towards machines, devices or instruments which perform the
subsequent processing on said articles, for example and in particular
(although
not exclusively) sewing or linking of the toe, pressing or the like.
According to a different aspect, the object of the present invention is to
provide a simple and effective method for correct orientation of tubular
knitted
articles, such as stockings and socks, picked up individually from a container
in
which they are placed randomly.
In substance, a first aspect of the present invention relates to a device for
handling tubular knitted articles having a first end and a second end
comprising
in combination:
- a first pick-up member and a second pick-up member for said tubular
articles,
which can be actuated alternatively to engage one end of the tubular articles;
- detection means to determine the orientation of the first and of the second
end of the tubular article, said first and second pick-up member being
controlled to alternatively engage the tubular article according to the
orientation of the tubular article detected by said detection means.
With an arrangement of this type it is unnecessary to perform detection on
the tubular article while it is traveling along the feed path in order to
subsequently
perform orientation by inverting, if necessary, the direction of feed along
the
transport duct, as is the case in conventional devices. On the contrary, once
the
tubular article has been spread and the position of the end to be engaged for
subsequent handling operations has been identified, one or other of the two
pick-
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up members is actuated selectively.
In a particularly advantageous embodiment of the invention, the pick-up
members are arranged and designed to engage each tubular article at the level
of the first end of the tubular article, typically the elastic band, and to
open it. It
would also be possible for the pick-up members to be designed to engage the
other end, i.e. the toe. The choice depends on the handling operations that
must
be performed on the tubular article in the subsequent processing steps. The
edge at which the article is to be engaged is typically elastic when the
article is a
sock, but it must be understood that this edge could also be non-elastic, for
example in the case of women's stockings or components of pantyhose.
Moreover, the opposite end can be an open toe, when the function of the device
is to feed (with the correct orientation) the articles to sewing or linking
means.
However, this second end could be a closed toe (sewn or linked), for example
when the article is handled to be sent for pressing operations. In general,
the
device according to the invention is useful each time tubular articles having
two
structurally different ends are required to be fed in a predetermined
direction to
members, means, devices or machinery for further processing, said articles
being picked up from a container in which they are placed randomly or in any
case fed to the device with a random and undefined orientation.
In a practical embodiment, the device according to the invention includes
an intermediate station, in which the tubular articles are positioned
individually
and in sequence in a substantially spread position, with the first and the
second
end approximately aligned with each other according to the longitudinal
extension of the tubular article, said first and said second pick-up member
being
associated with said intermediate station. The detection means can in this
case
be advantageously arranged and designed to determine the orientation of the
first and of the second end of the tubular article when it is in said
intermediate
station.
In a practical embodiment of the invention, the detection means are
arranged and produced to detect whether said first end of the tubular article
located in the intermediate station is positioned in proximity to the first or
second
pick-up member. Moreover, the pick-up members are controlled so that the
tubular article is engaged at its first end by the first or second pick-up
member at
the level of which said first end is positioned.
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Preferably, the detection means are optical means, capable of
distinguishing and discerning the two ends of the tubular article from each
other
on the basis of the shape of the end. For example, the detection means can use
a camera interfaced with an electronic processor, or in any case a control
unit,
equipped with image processing software. In a simpler version, the detection
means can include an arrangement of photocells, such as a linear matrix or
array, to identify the form of the end of the article which is interposed
between
the emitters and receivers of the photocells. Detection can be performed with
the
article at a standstill or with the article moving, on the basis of the
sequence with
which the photocells are intercepted by the article, said sequence being
determined by the form of the article. For example, a linear matrix, i.e. a
linear
array of photocells can be provided, controlled by specific software capable
of
identifying with which temporal sequence the photocells are obscured when the
article is gradually carried over them. This temporal sequence in fact depends
on
the shape, or form, of the contour of the article which in turn differs
between
edge and toe.
Notwithstanding the type of optical detection chosen, it is preferably
configured so that the use of particular measures is not required on the
articles,
such as strips or bands of fabric in a different coior to the body of the
article,
provided purely for the purpose of allowing discernment between the two ends.
In fact, these measures cannot always be implemented due to the type of
machinery used to produce the articles and, moreover, increase the cost of the
article. Further, the device according to the present invention can still be
used
with detection means which make use of the aforesaid measures to allow
recognition of the two ends.
Advantageously, a spreading system can be provided to longitudinally
spread said tubular articles and longitudinally align the first and the second
end
of the articles. Advantageously, in this case the two pick-up members can be
associated with the two ends of the spreading system.
According to an advantageous embodiment of the device according to the
invention, the spreading device has an inlet for the tubular articles at one
of its
longitudinal ends and an outlet for the spread articles, which can
appropriately
be positioned on the side, so that the individual spread articles are
delivered in a
direction orthogonal to the direction in which they were inserted in the
spreading
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member. The delivery direction of the tubular article from the spreading
member
is independent from the orientation of the article, which has not yet been
identified.
The articles can advantageously be inserted in the spreading system by
means of a pneumatic transport duct.
In a possible embodiment of the invention, a conveyor belt is combined
with the spreading system to remove the individual tubular articles from said
spreading system. This can define the base of an inner volume of said
spreading
system, the tubular articles being inserted in said inner volume.
According to a possible embodiment, each of the pick-up members has
opposed engaging elements designed and controlled to engage and move
opposite edges of textile material forming a corresponding end of the tubular
article away from each other, to open said end.
According to a possible embodiment of the invention, a respective transfer
device is associated with each pick-up member, arranged and designed to
transfer a tubular article engaged by the respective pick-up member towards
further manipulator members. These further manipulator members are designed
and arranged to position each tubular article on a tubular transport member,
either directly or after it has passed over a tubular reversing member.
?0 The manipulator members can include a gripper which receives the
tubular articles from one or other of said transfer devices. Advantageously,
the
transfer devices can each include a stretching member designed and arranged
to be inserted into the open end of the tubular article, supported by a
transfer
member which moves the stretching member transferring it towards other
manipulator members.
In a possible embodiment, each stretching member is supported by a
respective slide actuated with translational motion, forming part of a
respective
transfer device.
In an improved embodiment of the invention, the pick-up members can be
designed so as to directly perform transfer to further manipulator members,
such
as a gripper to load the tubular article onto a transport tube or the like.
In an advantageous embodiment, a single common stretching device can
be associated with the two pick-up members. In this case, each tubular article
is
carried to the common stretching device, which can comprise mechanical or
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pneumatic, or combined mechanical and pneumatic engaging means. One or
other of the pick-up members is then activated to pick up the tubular article,
the
end of which has been opened by the stretching device (which is preferably
located in an intermediate position between the pick-up mernbers) to transfer
the
tubular article towards other members, work stations or positions.
The invention also relates to a device for handling tubular knitted articles
having a first end and a second end, comprising: an operating position;
associated with the operating position, a first pick-up member and a second
pick-
up member for tubular articles which can be actuated alternatively to engage
one
or other of the two ends of the tubular articles.
The device can advantageously include detection means to determine the
orientation of the first and of the second end of the tubular article, said
first pick-
up member and said second pick-up member being controlled to engage the
tubular article alternatively, according to the orientation of the tubular
article
detected by said detection means, so that each tubular article is engaged
always
at the first end notwithstanding its orientation in the operating position.
The
detection means can be arranged and designed to determine the orientation of
the tubular article when it is in the operating position. A control unit can
be
provided, programmed to receive information from said detection means and to
control actuation of one or other of said first pick-up member and of said
second
pick-up member according to the information received from said detection
means.
According to a further aspect, the invention relates to a device for
handling tubular knitted articles, such as stockings or socks, with a first
end and
a second end, provided with two substantially symmetrical pick-up members
which can be activated alternatively to engage one or the other of the ends of
the
article, in combination with detection means to determine the orientation of
the
article, so that the article is always engaged at one of the two ends by one
or the
other of the pick-up members, according to the detection implemented by the
detection means. According to a possible embodiment, the pick-up members can
each include a pair of fingers which can be inserted into the corresponding
end
of the tubular article. The end which is engaged by one or by the other of the
pick-up members can, for example, the elastic edge of the article.
According to a possible embodiment, associated with the two pick-up
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members is a single common stretching device, that is, a member which opens,
stretches or spreads the end of the tubular article to be engaged by the pick-
up
members. This common stretching device can have a pair of opposed engaging
members, mechanical, pneumatic or a combination of mechanical and
pneumatic, or of other suitable type, which are arranged and designed to
engage
and move apart opposite portions of an edge surrounding one or the other of
the
ends of the article. In a preferred embodiment, the common stretching device
is
arranged in an intermediate position between the stand-by positions of the
pick-
up members.
Besides being controlled to alternatively engage the tubular article
(depending on how said article is oriented), so that said article is always
engaged at the same end, the pick-up members can also be designed and
controlled to transfer the tubular article thus engaged towards further
manipulator
members, such as a transfer device, a loading tube, a gripper for subsequent
transfer to a loading tube, a manipulator to insert the tubular article onto
an
inspection, pressing or finishing template, or for other operations, such as
those
known in the field of manufacturing stockings, pantyhose, tights and other
hosiery articles.
The tubular articles can be conveyed with any known means through
various stations of which the device is composed, such as and typically a
single
or double spreading station, a reading station, a station where the ends are
engaged. According to a particular and currently preferred embodiment, said
transfer is obtained by arranging the tubular article transversely on a
continuous
conveyor, i.e. composed of a continuous member which moves along a closed
path, such as a mat, a belt, a track, a plurality of slats joined to one
another on a
flexible belt or chain member, or the like.
According to another aspect, the invention concerns a method for handling
tubular articles with a first end and a second end, comprising the steps of:
- picking up a tubular article from a container, in which said articles are
arranged randomly;
- transferring said article to an operating position, with its ends
approximately aligned according to a direction of longitudinal extension of
the tubular article;
- recognizing which of the two ends of said article is the first end;
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> engaging the tubular article at the first end and moving it away from said
operating position.
According to a possible embodiment, the method can include the following
steps:
- arranging in said operating position a first pick-up member and a second
pick-up member;
- controlling said first pick-up member and said second pick-up member to
actuate either said first pick-up member or second pick-up member in
proximity to which said first end of the tubular article is arranged, to
engage said first end of the tubular article.
In a possible embodiment, the first end of the tubular article, typically the
elastic band, is engaged and opened by the respective pick-up member. In
another possible embodiment of the invention, the article can also be engaged
at
the toe and said toe can, for example, be opened.
According to another aspect the invention relates to a method for handling
tubular articles with a first end and a second end, comprising the steps of:
- arranging individual tubular articles sequentially in an operating position;
- engaging each tubular article at the first end and moving it away from said
operating position.
The method can also include the steps of:
- arranging in said first operating position a first pick-up member and a
second
pick-up member;
- engaging each tubular article alternatively with said first pick-up member
or
with said second pick-up member.
In an improved embodiment of the invention, the method also includes the
steps of:
- recognizing the position of the first end of an article in the operating
position; and
- actuating one or other of said first and second pick-up members always to
engage the first end of the tubular article.
According to a possible embodiment of the method according to the
invention, the first end of the tubular article can be engaged by a common
stretching device, and one or the other of at least two pick-up members can be
made to cooperate with said end, according to the orientation taken by the
article
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in the work station.
The invention also relates to a device for handling tubular knitted articles
having a first end and a second end, including: a working position; associated
with said working position, a first pick-up member and a second pick-up member
for the tubular articles, which pick-up members can be activated alternatively
to
engage one or the other of the two ends of the tubular articles. According to
a
possible embodiment the pick-up members are designed to open the ends of the
tubular article which must be engaged by the pick-up member. In a further
possible embodiment of the invention, the first pick-up member and the second
pick-up member are combined with a common stretching device, which opens,
i.e. stretches the end of the tubular article which must be subsequently
engaged
by the corresponding pick-up member.
According to an advantageous embodiment of the invention, the first and
the second pick-up member in said working position are controlled to engage
each tubular article in said working position always at the first end, which
can be,
for example, the edge or the toe of articles in the form of stockings or
socks. The
pick-up members are controlled so that they are always activated selectively
and
alternatively according to the orientation taken by the articles in the
operating
position. In practice, therefore, the invention consists of a device which by
means
of at least two pick-up members, engages each tubular article which is carried
to
a working position or workstation always at a same end, regardless of the
random orientation with which said article is placed in the working position
or
workstation.
The pick-up member can be a member which also opens the tubular
article at the end engaged by the pick-up member. In this case, a system to
engage the tubular article can be associated with each pick-up member, to
subsequently transfer said article to a different workstation. In another
embodiment, this pick-up member can be composed of a member to engage the
article once it has been stretched at the end thereof, for example by a common
device in an intermediate position between the two pick-up members. The pick-
up member can be composed of a mechanical member which also transfers the
tubular article to a subsequent station.
Further advantageous embodiments of the method and of the device
according to the invention are set forth in the appended dependent claims and
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will be described in greater detail with reference to possible non-limiting
examples of embodiment of the invention.
Brief description of the drawings
The invention will now be better understood following the description and
accompanying drawing, which shows a non-limiting practical ernbodiment of the
invention. More specifically, in the drawing:
Figure 1 shows a perspective view of the container for the tubular knitted
articles and of the means which pick up individual articles from the container
to
send them along a pneumatic path;
Figures 2 and 3 show perspective views of means and devices to perform
orientation of the tubular articles;
Figure 4 shows a plan view of the device in Figures 2 and 3;
Figure 5 shows a side view according to V-V in Figure 4;
Figure 6 shows a perspective view of the lower part of the devices in
Figures 2 and 3 with parts removed;
Figure 7 shows a perspective view of the spreading device of the tubular
articles;
Figures 8 and 9 show perspective views according to different angles and
in different positions of the various members of the transfer devices of the
tubular
articles and of the gripper which inserts the appropriately oriented tubular
articles
over the transport tube;
Figure 10 shows a longitudinal section of the spreading member;
Figure 11 shows an enlargement of a detail in Figure 10;
Figures 12 to 15 show a operating sequence of the spreading device;
Figures 16 to 20 show an operating sequence, with which one of the
transfer devices transfers the tubular article to the gripper to allow
subsequent
transfer to the tubular transport or reversing member;
Figures 21 and 22 show axonometric views according to two different
angles of a different embodiment of the invention;
Figure 23 shows a side view according to XXIII-XXIII in Figure 22;
Figure 24 shows a{ongitudinal section of the spreading system to spread
the articles in the embodiment according to Figures 21-23 and of a
corresponding pick-up mechanism of the articles;
Figure 25 shows a perspective view of the pick-up mechanism in Figure 24;
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Figure 26 shows a front view of the pick-up mechanism in Figure 25;
Figures 27 and 28 show axonometric views according to two different
angles of the spreading system and of the pick-up mechanism in Figure 24 with
the pick-up mechanism separate from the spreading system;
Figure 29 shows an axonometric view, the same as the one in Figure 27,
but with the spreading system and the pick-up mechanism in a coupled
arrangement;
Figures 30 show an axonometric view of the device in Figures 21 to 23,
wherein the mechanical parts of all the stations have been renioved with the
exception of the parts of the station for reading or detecting the orientation
of the
article, limited to the members for moving the articles;
Figures 31 and 32 show said members for moving the articles in two
different operating positions;
Figure 33 shows a perspective view of the stretching members which open
the end of the tubular article;
Figures 34 to 39 show axonometric views in various operating positions of
the pick-up members, of the respective actuators and of the mechanical
elements associated therewith;
Figure 40 shows a front view of the pick-up members, according to the line
XL-XL in Figure 41;
Figure 41 shows a plan view according to XLI-XLI in Figure 40;
Figure 42 shows a side view according to XLII-XLII in Figure 41;
Figures 43A to 43Q show schematic views representing an operating cycle
of the device shown in Figures 21-42.
Detailed description of preferred embodiments of the invention
Embodiment in Figures 1 to 20
A device incorporating the present invention and which has the function of
loading socks provided with an elastic band and an open toe onto a transport
tube to convey the individual socks to a sewing machine is described below.
However, it must be understood that the principles and the specific technical
solutions described herein can also be utilized in other machinery, which
handle,
for example, tubular articles with a non-elastic open band and/or with the toe
already sewn, for example to load the articles onto pressing templates, in a
packaging machine, or the like.
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Figure 1 shows a perspective view of the container in which the tubular
articles are placed randomly to be subsequently picked up, the pick-up means
and the beginning of the pneumatic transport path with which the individual
tubular articles are sent to the devices provided for their orientation.
In Figure 1 the number 3 indicates a container which receives randomly
arranged tubular articles which can, for example, come from a series of
circular
knitting machines. The container 3 can rotate according to the arrow f3 about
a
vertical axis by rneans of a motor, not shown. The number 5 generically
indicates
a pick-up device, of known type, which moves vertically according to the
double
arrow f5 along a vertical guide, at the level of which the inlet 7A of a
pneumatic
transport duct 7 is positioned. The individual tubular articles picked up by
the
pick-up device 5 are sucked with random orientation through the inlet 7A into
the
suction duct 7. The latter extends to a spreading member which is positioned
in a
subsequent station of the device, illustrated in detail with reference to the
subsequent figures.
Connected to the pneumatic transport duct 7 is a pneumatic return duct 11,
which transfers, through an unloading device 13, any tubular articles which
cannot be further handled, for example, when the pick-up device 5 due to an.
operating error picks up two tubular knitted articles simultaneously and feeds
them to the pneumatic transport duct 7.
The numbers 105 and 111 indicate gate valves or valves used to open and
close the individual branches of the pneumatic paths, and in particular the
pneumatic duct 7 and the pneumatic return duct 11. The number 103 indicates a
connection with a suction line, not shown, for example connected to a suction
fan.
With reference to Figures 2 to 11, the members used to correctly orient
each tubular knitted article fed into the pneumatic transport duct 7 will now
be
described.
In Figures 2 and 3, the number 21 indicates as a whole the assembly of the
machines, devices and equipment required to orient the tubular articles and
transfer them to a tubular transport member 23 or to a tubular reversing
member
25. The tubular transport member 23 can be part of a more complex machine,
optionally with several stations, used to transfer the tubular knitted article
to a
sewing or linking machine. The machine incorporating the transport member 23
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and the sewing machine do not form the object of the present invention and,
therefore, are not represented.
The tubular reversing member 25 is employed, as will be more apparent
below, when the individual tubular articles fed to the assembly of equipment
21
must be reversed to turn the finished tubular article inside out.
With specific reference to Figures 2 to 5, the number 7B indicates the end
of the pneumatic transport duct 7, opposite the inlet 7A (Figure 1). The end
section 7B is represented with a rectangular shape, but this is not strictly
essential.
The end 7B of the transport duct 7 terminates at a first end of a spreading
device indicated as a whole with 27, inside which each tubular article fed
through
the pneumatic duct 7 is spread to position the first end (e.g. the elastic
band) and
the second end (e.g. the toe to be closed) of the tubular article aligned
according
to the longitudinal extension of the tubular article.
The internal structure of the spreading device 27 and its operating modes
will be described in greater detail with reference to Figures 10 to 15. For
the
moment it is sufficient to point out that the individual tubular articles
inserted onto
the spreading device 27 each time with a random orientation (i.e. with the
first
end or the second end being the leading end with respect to the direction of
insertion) are delivered from the side of the spreading device 27 again in a
random orientation, but with the aforesaid two ends aligned according to the
longitudinal extension of the tubular article. The base of the spreading
device 27
is defined by a conveyor belt 29, which moves according to the arrow f29
controlled by a motor 30 (Figure 3).
A load-bearing structure 31, which also supports the spreading device 27
and the conveyor belt 29, supports a second conveyor belt 33 provided with a
movement according to the double arrow f33 in a direction oriented
substantially
through 90 with respect to the direction f29 of the movement of the conveyor
belt 29. The motor 35 (Figures 2 to 4) provides the movement for the conveyor
belt 33.
The conveyor belt 33 is supported by side elements 37, to which the motor
is also fastened, which can move towards and away from each other with
respect to the conveyor belt 29 below moving in the direction of the double
arrow
f37 for the purposes described below. The lifting and lowering movement of the
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side elements 37 is provided by an actuator 39 (Figure 3) of pneumatic,
hydraulic
or similar type.
When an individual tubular article is delivered from the side of the
spreading device 27 conveyed out of it by the conveyor belt 29, it must be
transferred with a movement parallel to its longitudinal extension under a
detection means to detect which of the two ends is the toe, or the elastic
edge. In
substance, the individual tubular article must be arranged at the level of at
least
one system capable of recognizing and distinguishing the two ends of the
tubular
article from each other. In the embodiment illustrated schematically here, the
detection means include a camera 41 (represented schematically only in Figure
4) or another suitable viewing system which, for reasons of economy, is
provided
only on one side of the conveyor belt 29, but could also be provided on the
opposite side. Instead of a viewing system, such as a camera 41 or the like,
the
detection means could be of another kind. For example, systems could be
provided which are capable of distinguishing the color of an elastic band or
strip
surrounding the open toe of the tubular article, and which has a different
color
from the rest of the fabric of the tubular article. In this case the detection
means
could, for example, include photocells or the like. However, this solution,
has the
drawback of increasing the production cost of the articles.
Yet again, alternatively or in combination, a system capable of recognizing
the presence of conductive materials, such as a metal thread, inserted in the
band surrounding the toe of the tubular article to be closed, could be
provided as
detection means.
Yet again, alternatively or in combination, detection means could be
provided which are based on recognition and discernment of the two ends of the
tubular article through characteristics of elasticity, thickness, or of
another
nature, of said article.
Alternatively or in combination, in a preferred solution it would also be
possible to use a system of photocells arranged according to a geometrical
configuration which allows recognition of the form of the end of the article
which
is interposed between emitters and receiver of the photocell, to distinguish
the
elastic edge from the toe. Various types of devices having this functionality
are
known and those skilled in the art can easily select the most suitable
detection or
recognition device for the particular application.
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In any case, the detection means can be single or double, i.e. present on
only one side or on both sides of the conveyor belt 29, although to economize
it
would be preferably for them to be provided only on one side.
As the tubular knitted article, which is delivered from the side of spreading
device 27, is positioned on the conveyor belt 29, 'it must be translated
longitudinally to be taken with one of its ends, which has yet to be
determined
whether it is the toe or the elastic edge, to the level of the detection means
41.
The transverse conveyor belt 33 positioned over the conveyor belt 29 has the
function of translating the tubular article parallel to its longitudinal
extension,
according to the arrow f33, to take the end closest to the detection means 41
and
under said means. To allow this translational movement of the tubular knitted
article the surface of the conveyor belt 29 has a coefficient of friction at
least
slightly lower than the coefficient of friction of the conveyor belt 33, so
that when
the conveyor belt 33 is taken with its lower branch to press against the
tubular
article which is located on the conveyor belt 29, the movement imparted by the
motor 35 to the conveyor belt 33 causes the tubular article to slide on the
upper
surface of the conveyor belt 29 until it is under the detection means 41.
It would also be possible to move the detection means 41 while the article
remains at a standstill.
1110 As mentioned, the purpose of these detection means 41 is to recognize
whether the end of the tubular article positioned under them is the first end
(e.g.
the elastic band) or the second end (e.g. the toe), in order to communicate
the
effective orientation of the tubular article on the conveyor belt 29 to a
central
control unit (indicated schematically with 42 in Figure 4).
As the tubular article must be removed from the operating station or
position, or intermediate station, in which the spreading device 27 and the
conveyor belt 29 are located always with one of its ends being the leading
end,
i.e. always with the same orientation, for each tubular knitted article to be
inserted over the tubular reversing member 25, or over the tubular transport
member 23 always with the correct end, and typically with the elastic band,
two
groups of essentially symmetrical members 51 A and 51 B are arranged at the
two
sides of the conveyor belt 29, which are used to open and stretch the end of
the
tubular article to be subsequently inserted over one or over the other of the
tubular members 23, 25. These groups 51A, 51B include pick-up and transfer
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members for the tubular articles. The one of said group or pick-up members
51A,
51 B is actuated, at the level of which the end of the tubular article is
positioned,
which is to be opened and inserted over one or other of the members 23, 25.
The members and the mechanisms forming the two symmetrical groups 51A,
51 B are indicated with the same reference numbers followed by the letters A
or
B.
Each of the groups 51A, 51B firstly has a fixed suction surface 53A, 53B
provided on a flat sliding surface 55A, 55B positioned along the side of the
conveyor belt 29. Arranged over the suction surface 53B is a respective pick-
up
means 57A, 57B provided with a vertical movement imparted by an actuator
59A, 59B. The pick-up means 57A, 57B can thus move towards the
corresponding suction surface 53A, 53B and away therefrom. The suction
surface 53A, 53B and the corresponding pick-up means 57A, 57B with its
actuator 59A, 59B form means to alternatively engage the elastic band, i.e.
the
first end of the tubular article which is brought over the suction surface 53A
or
53B to open said end.
Each group 51A, 51B also includes a stretching device, composed in this
embodiment of a pair of fingers 61A or 6113, In the Figures 2, 3, 4 and 5, the
fingers 61A, 61B are represented in the two different positions, vertical and
horizontal respectively, which the fingers take during the operating cycle as
will
be explained in greater detail below. These fingers are in turn supported by
respective transfer devices, which transfer the articles engaged by the
stretching
devices composed of the fingers 61A, 61B towards further handling means, as
will be described below.
Figure 8 shows the fingers 61A and 61 B in various possible positions. More
specifically, the fingers 61A are represented in Figure 8 in their vertical
position,
while the fingers 61 B are represented in the horizontal and vertical
arrangements, in two distinct positions the pair of fingers can take along the
front
of the conveyor belt 29 to pick up the individual article and transfer it
towards a
gripper, described below, which inserts the article over one or other of the
tubular
members 23 and 25.
The two fingers 61A, 61B of each pair can be moved towards and away
from each other by means of a piston-cylinder actuator 63A, 63B. The pair of
fingers, with the respective actuator 61A, 63A or 6113, 63B, are supported on
a
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support 65A or 65B movable vertically according to the double arrow f65
controlled by an actuator 67A or 67B (see in particular Figures 5 and 6).
The piston-cylinder actuator 67A or 67B is supported by a slider 69A, 69B.
Integral with the slider is a rack 71A or 71B, meshing with which is a pinion
73A,
or 73B, keyed on a shaft 75A or 75B, attached to the opposite end of which are
the fingers 61A, 61B with the respective actuator 63A, 63B which moves them
towards and away from each other. With this arrangement, a vertical lifting
and
lower movement of the support 65B or 65A controlled by the actuator 67B or
67A, besides a lifting and lowering movement of the respective fingers 61 B,
61A,
also causes rotation of the fingers about the axis of the corresponding shaft
75B,
75A.
The two sliders 69A and 69B are supported (see in particular Figure 6) by
respective slides 77A, 77B. The two slides 77A, 77B move slidingly along a
common guide 79 and their movement is controlled by two parallel threaded bars
81A and 81B made to rotate by respective motors 83A, 83B. The threaded bars
81A, 81B engage in female screws 85A, 85B integral with the slides 77A, 77B.
The motors 83A, 83B therefore cause movement of one or other of the stretching
devices composed of the pairs of fingers 61A, 61 B according to the double
arrow
f61 (Figure 6). The slides and sliders form the transfer devices or means
which
support the pairs of fingers towards the central zone of the device where they
transfer the tubular articles to a gripper described below, which then inserts
them
over one or other of the tubular members 23, 25.
Each slide 77A, 77B in turn supports a guide 87A, 87B on which the
respective slider 69A, 69B slides. This slider is provided with a movement
according to the double arrow f69 in a direction orthogonal to the direction
of the
guide 79. This movement according to the arrow f69 is imparted to one or other
of the two sliders 69A, 69B by a cam and tappet mechanism. This mechanism
has a track which forms a cam profile 91, inside which two idle pins 93A, 93B,
integral with respective sliders 69A, 69B, engage. The profile of the channel
91 is
substantially symmetrical with respect to a vertical median plane and is
configured so that a translational movement of one or other of the sliders
69A,
69B with their respective slides 77A, 77B in the direction of the arrow f61
from
the position farthest from the median plane to the position closest to the
median
plane of the device causes the slider 69A, or 69B to move away with respect to
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the position of the spreading device 27.
With reference to the example in Figure 6, the pair of fingers 61A with the
respective members supporting them are represented in two distinct positions,
respectively the external side position (on the right in figure 6), and the
intermediate or internal position (central in Figure 6). On the other hand,
the
fingers 61 B with the respective members which support and move them are in
their external side position.
The functions of the various movements described herein will be explained
below with reference to an operating sequence of the entire device.
Figure 7, 10 and 11 show in greater detail the configuration of the
spreading device 27. It includes a box structure 150 with a rectangular
section,
connected to which are the end 7B of the pneumatic transport duct 7 and a
suction mouth 151. The box structure 150 has a side panel 153 attached to a
piston-cylinder actuator 155 supported by the upper horizontal wall of the box
structure 150. The actuator 155 can control a lifting and lowering movement of
the side panel 153 to open and close the box structure 150. The conveyor belt
29, runs along the bottom of the box structure 150, in substance defining the
lower surface of the compartment or inner volume with rectangular section of
the.
spreading device 27. The lifting movement of the side panel 153 allows the
210 tubular article inside the spreading device 27 to be delivered from the
side and
transferred out of the spreading device by the conveyor belt 29.
In the central zone of the box structure 150 the spreading device has
movable pressers 161 actuated by actuators 163 (five in number in the example
shown) which have the dual function, described in greater detail below with
reference to an operating sequence, of reducing the cross section of the
compartment or inner volume of the spreading device 27, reducing the vertical
dimension, during the spreading step of the tubular, article, and of allowing
complete and correct spreading of said article also at its end which is
inserted
into the spreading device 27 first.
As can be seen in particular in Figures 10 and 11, a screen 165 is arranged
between the inside of the spreading device 27 and the suction mouth 151 to
prevent the tubular articles penetrating the spreading device 27 from being
sucked inside the suction mouth 151. In the example shown the screen 165 is
arranged inclined to define a substantially cuneiform volume, arranged at the
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narrow end of which is a retention member 167, controlled by a piston-cylinder
actuator 169 (Figure 11), provided to retain the end of the tubular article
orientated forward with respect to the direction of insertion of the tubular
article in
the spreading device 27. Due to the configuration of the device, the retention
member 167 engages one article at a time. If two tubular articles are
accidentally
fed into the box structure 150 one of them is engaged by the retention mernber
and the other is carried back by suction and returned to the container 3.
Consequently, the device 27 also functions as a separator and not just as a
spreading device.
Alternatively, the screen 165 can be arranged on a surface approximately
orthogonal to the direction from which the tubular articles are fed and the
retention member can, for example, be composed of a gripper.
The box structure 150 is supported slidingly in the direction of the double
arrow f150 to perform a transverse movement with respect to the direction of
movement f29 of the conveyor belt 29. This transverse movement according to
f150 of the box structure 150 of the spreading device 27 is imparted by a
piston-
cylinder actuator 171 and its purpose will be described with reference to an
operating sequence of the machine.
Arranged in an intermediate position along the front of the conveyor belt 29
are the tubular members 23 and 25, the latter supported by a fixed structure
26,
while the tubular member 23 is attached, for example, to a conveyor, not
shown,
of a machine which loads the tubular articles onto the sewing or linking
machine.
At the level of the tubular members 23, 25 (which are superimposed and
substantially coaxial with each other), is a gripper, indicated as a whole
with 180,
the function of which is to receive the individual tubular articles picked up
from
the pair of fingers 61A or 61B, stretch the elastic band and insert it
alternatively
over the upper tubular member 25 or over the lower tubular member 23.
The gripper 180 has a rotational movement through 180 around a vertical
axis, imparted by means of a piston-cylinder actuator 183 supported by a slide
185 which also supports the gripper assembly 180. The piston-cylinder actuator
183 controls a rack 187 (see in particular Figure 16), meshing with which is a
pinion (not visible) integral with a shaft which supports the gripper 180. The
linear movement of the piston-cylinder actuator 183 thereby causes rotation of
the entire gripper assembly 180 through 180 about the axis A-A (Figure 9).
The
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purpose of this rotation is to allow the gripper to transfer the tubular
article
engaged by it (in the manner to be described below) alternatively to the
tubular
member 25 or to the tubular member 23.
The slide 185 is provided with a vertical movement according to the double
arrow f185 along a vertical guide 188. The vertical movernent is obtained by
means of a transmission belt 189 and a motor 190 arranged at the upper end of
the guide 188. The movement according to the double arrow f185 allows the
gripper to transfer the tubular article to the corresponding end of the
tubular
member 25 or 23.
The gripper 180 is composed of two flat jaws 201 supported by brackets
203. The two jaws 201 each cooperate externally with a pair of bars 205 which,
as shall be apparent below, are used to block the elastic band of the tubular
article on the jaws 201. The movement of the jaws 201 towards and away from
each other is controlled by two piston-cylinder actuators 207, 209.
Operation of the entire machine described above is illustrated with specific
reference to Figures 12 to 20, in which Figures 12 to 15 show in particular
the
operating functions of the spreading device 27, while Figures 16 to 20 show
the
methods with which a tubular article, spread in the spreading device 27 and
the
orientation of which has been recognized, is loaded on one or other of the
tubular members 23, 25. The various members and actuators of the device are
controlled, to perform the operations described below, by a microprocessor or
by
a programmable unit indicated schematically with 2 only in Figure 4 and
connected to the various actuators, encoders and other means, not described
and known, employed on the device to control the various movements.
An individual tubular article M is picked up by the pick-up device 5 from the
rotating container 1 and sucked inside the pneumatic transport tube 7, which
leads into the inner compartment of the spreading device 27. The suction that
transports the tubular article from the inlet 7A of the pneumatic duct 7
inside the
spreading device 27 is applied through the suction mouth 151.
In Figure 12 the tubular article M is entering, sucked through the mouth
151, the compartment of the spreading device 27 and reaching with one of its
ends (which can either be the elastic band or the toe without distinction and
randomly) the inclined end screen 165. Travel of the tubular article M
terminates
according to the arrow F against said screen and the tubular article is
clamped
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(Figure 13) by the retention member 167 actuated by the actuator 169. At this
point the individual pressers 161 associated with the spreading device 27 can
be
lowered to halfway through their travel by the actuators 163 to take the
position
shown in Figure 13. In substance, this reduces, at least in the central zone,
the
cross section (more specifically the height) of the inner compartment of the
spreading system or device 27.
By inverting suction inside the duct which connects in 7B with the inner
compartment of the spreading device 27, the tubular article M is pulled and
spread with a force applied by the air flow in the direction of the arrow Fl
in
Figure 13, while the end of the tubular article M engaged against the screen
165
remains fastened there.
At this point, the tubular article M is in the spread position inside the
volume
of the spreading device 27. If two tubular articles are fed inside the
spreading
device 27 by error, the second tubular article will not be engaged by the
retention
member 167, thanks to the particularly narrow configuration of the end zone of
the cuneiform volume defined by the screen 165 and will therefore be unloaded
through the device 13 and the unloading duct 11 into the container 1 through
inversion of suction. In fact, in this step suction inside the spreading
device 27, a
portion of the duct 7 and the pneumatic duct 11 is produced through the
suction
mouth 103, the gate valve 111 being open and the gate valve 105 being closed.
After the tubular article M has reached the spread position inside the
volume 150 of the spreading device 27, the box structure of the spreading
device
is translated to the left (in the figure) by means of the piston-cylinder
actuator
171 to take the position in Figure 14. In this way the tubular article M is
practically positioned entirely over the conveyor belt 29 which defines the
base of
the inner compartment of the spreading device 27. In the subsequent operating
step (Figure 15) the presser 161 which is closest to the end of the article M
that
entered the inner compartment of the spreading device 27 last is lowered to
press the article M against the conveyor belt 29 below. As the tubular
articles M
which are in the container I are all substantially of the same dimension, i.e.
of
the same size, it is known a priori which of the five pressers 161 is
positioned
closest to this end of the tubular article M. This allows the correct presser
to be
actuated by the control unit 28. Alternatively, optical sensors could be
provided
inside the spreading device 27 to identify the position of the end of the
tubular
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article M that entered the inner compartment of the spreading device 27 last.
The
other pressers 161, positioned to the left of the lowered presser 161 (i.e. on
the
opposite side with respect to the end in which the screen 165 is positioned),
can
also be moved downwards, to prevent any portion of the article M projecting
slightly from the presser in question from being folded over itself when
suction
through the screen 151 is actuated again.
With the tubular article M engaged in this way against the upper surface of
the conveyor belt 29, the box structure 150 of the spreading device 27 can be
translated again from left to right (in the figure) by the actuator 171 to be
returned
to the position in Figure 15. In this step suction can also be actuated again
through the suction mouth 151 to correctly spread the end of the tubular
article M
which was previously engaged by the retention member 167 and which may not
be perfectly aligned with respect to the longitudinal extension of the article
M.
At the end of these operations the side panel 153 of the box structure 150
of the spreading device 27 is lifted by the actuator 155 and the conveyor belt
29
is actuated to transfer the spread tubular article out of the inner
compartment of
the spreading device 27.
In a subsequent step, not shown, the tubular article M is translated in a
transverse direction with respect to the direction of feed of the conveyor
belt 29,
by means of the conveyor belt 33 until its end which entered the spreading
device 27 last is under the camera 41 or other detection means arranged on one
of the two sides of the conveyor belt 29. The camera is capable of
distinguishing
whether the end of the article under it (i.e. the end which entered the
spreading
device 27 last) is the toe or the elastic band of said article, i.e. if it is
the second
or the first end of the article.
As the article M must be engaged by pick-up means 53B, 57B or 53A, 57A
at the level of its elastic band, according to the detection performed by the
camera detection means 41 or other equivalent devices, the unit 28 controls
the
subsequent movement of the conveyor belts 33 and 29, which is coordinated to
take the tubular article M with its elastic edge at the level of the pick-up
means
and in particular with its elastic band resting on the suction surface 53A or
53B.
Evidently, the tubular article M is in this way transferred from one or other
of
the symmetrical groups 51A, 51B according to the position of the elastic band,
which is random as the tubular article is picked up from the container I in a
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random position.
Figure 16 shows the subsequent step in which the tubular article M has
already been positioned with the coordinated movement of the conveyor belts
29, 33, with its elastic band B at the level of the group 51A. Evidently, in
this
example the tubular article M entered the spreading device 27 with its elastic
band facing forward and with the toe P representing the second end of the
tubular article downstream of the elastic band B with respect to the direction
of
feed of the tubular article M inside the pneumatic transport duct 7.
If the tubular article M had entered the suction duct 7 with the opposite
orientation, i.e. with the elastic edge B at the back and the toe P at the
front, it
would have been transferred with the elastic band B at the level of the group
51 B. In the example illustrated the subsequent steps will be performed on the
elastic band B by the group 51A. If the tubular article M had been facing in
the
opposite direction the group 51B would have been used instead, to perform the
subsequent operations.
Froni the layout in Figure 16, the tubular article M is engaged by the pick-up
means 53A, 57A, which move reciprocally towards each other with the elastic
band B of the article interposed therebetween. By actuating suction through
the
suction surfaces 53A and actuating the pick-up means 57A and subsequently
reciprocally moving these two elements away from each other by means of the
actuator 59A, the opposed edges forming the elastic band B of the article are
slightly distanced. The fingers 61A, which in Figure 16 are shown parted, are
moved towards each other and inserted inside the open elastic band B.
Subsequently, the fingers are parted to stretch the band B elastically.
Once the band B has been engaged by the stretching fingers 61A, by
means of the handling members described with specific reference to Figure 6,
these fingers are translated from the side position to the intermediate
position
(the two positions are indicated in Figure 6). The fingers 61A are also
rotated
clockwise through 900 to be taken to the vertical position.
When the fingers 61A are in the intermediate position they are placed
above the gripper 180, as shown in the layout in Figure 17. The tubular
article M
is still engaged with its elastic band B by the parted fingers 61A. The jaws
201 of
the gripper 180 are moved towards each other, so that a relative vertical
movement between the fingers 61A and the gripper 180 carries these members
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to the relative position in Figure 18, with the fingers 61A under the central
brackets 203 which support the plates forming the jaws 201 of the gripper 180.
As the jaws 201 are moved towards each other and the fingers 61A move with
respect thereto until they are lowered under the brackets 203, the tubular
article
M is transferred with this relative movement from the fingers 61A to the jaws
201,
the elastic band B being arranged around the jaws 201 of the gripper 180 as
shown in Figure 18.
After reaching this position, also visible in the perspective view in Figure
19,
the jaws 201 of the gripper 180 can open to stretch the elastic band B of the
article M until it has a quadrangular cross section as shown in Figure 20. The
end of the tubular article M composed of the elastic band B is in this way
enlarged to a sufficient extent to allow the gripper 180 to transfer the
tubular
article onto one or other of the two tubular members 23 or 25.
The overturning movement through 180 degrees which the gripper 180 can
perform by means of the actuator 183 allows the mouth of the tubular article
to
be positioned facing the lower tubular member 23 (position in Figure 20) or
facing the upper tubular member 25.
When the tubular article M is fed from a double cylinder circular knitting
machine it is already reversed, i.e. with its inner surface facing outwards.
In this
case the tubular article M is inserted directly onto the lower tubular
transport
member 23. If, on the other hand, the tubular article M is fed from a single
cylinder circular machine, it must be reversed to take the surface normally on
the
inside to the outside before it is sewn. For this purpose, the gripper 180
rotates
through 180 about the horizontal axis to insert the elastic edge B of the
article
over the upper tubular reversing member 25, which in a known way reverses the
tubular article by means of additional members, not shown. The reversed
tubular
article is then transferred to the lower tubular transport member 23.
As will be clear from the description above of the structure and of the
functions of the various members of the machine, it is capable of performing
the
following functions in parallel:
- spreading and separating in the device 27;
- detecting the end of the article on the conveyor belt 29;
- opening the edge of the end.
Therefore, three distinct tubular articles, on which the aforesaid operations
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are performed in succession, can be present at all times in the machine.
Embodiment in Figures 21 to 43
Figures 21-43 show another embodiment of the device according to the
invention. The same numbers indicate the same or corresponding parts in the
various figures. In this embodiment, the device can be combined with a
container
for tubular articles, associated with which is a means to pick up the
individual
articles with a configuration substantially the same as the one shown in
Figure 1
described above. The container for collection of the articles to be handled
and
the pick-up members of the articles can also differ from those shown in Figure
1
and be designed according to other criteria known in the state of the art or
within
the ability of those skilled in the art. The only relevant fact is that the
articles,
preferably already separated one from the other, are fed to the device that
performs orientation thereof.
The members which spread the tubular articles longitudinally, detect their
orientation and pick-up the end of the article to be handled are shown in
Figures
21 to 42. They will be described in detail hereunder and operation thereof
will
subsequently be explained on the basis of Figures 43A-43Q. They can be
positioned at least partly overlapping the container shown in Figure 1, in
order to
reduce the overall dimensions.
The suction duct 7 (Figure 1) feeds the individual tubular articles to a
device represented as a whole in Figures 21 to 23, and indicated generically
with
501. This device comprises a conveyor 503 which moves the individual articles
forward in steps according to arrow F. The slatted conveyor 503 is composed of
individual slats 503A, constrained to a flexible member, such as one or more
chains, not shown. Strips 503B are fastened to some of the slats 503A to
define
individual seats for the articles to be moved forward along the path of the
device.
As in the embodiment shown in Figures 1 to 20, in the device 501 the
individual articles fed to the device are also first spread longitudinally, it
being
understood that each article is spread with the longitudinal extension thereof
oriented transversely with respect to the direction of feed F of the conveyor
member 503. To spread each article, the device 501 has a double station and a
double spreading system or device described hereunder. In Figure 23, the
numerals 507 and 509 indicate as a whole the two stations or positions in
which
the two spreading members that perform longitudinal spreading of each article
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are located. More specifically, a first spreading system 510, to which the
suction
duct 7 connects in 7B and the structure of which is described in detail
hereunder
with reference to Figures 24 to 29, is located in the station 507.
The connector 7B leads into a compartment with a rectangular cross
section 513 which has, at the opposite end with respect to the connector 7B, a
shutter 515 having the function of modifying the conformation of the section
of
passage defined by the compartment 513, constricting it in a specific
operating
phase. The shutter 515 has a shutter element 515A controlled to translate
according to the double arrow f515 orthogonal to the longitudinal axis of the
compartment 513, by means of a piston-cylinder actuator or other suitable
actuator shown at 517. As can be seen in particular in Figure 27, the shutter
515
has a shape with a semi-circular lower edge, or more generally with a curved
and convex cross section, approximately the same as the shape of the semi-
circular cross section of the end portion 513A of the suction compartment 513.
When the shutter element 515A of the shutter 515 is in the position shown in
Figures 24 and 27, it defines with the inner wall of the portion 513A of the
compartment 513 a passage with a narrow and shaped cross section, extending
approximately in a semi-circumference, which (as will be explained hereunder)
tends to flatten the tubular article.
Integral with the spreading system 510 is a suction mouth 521, connected
to which is a suction duct 523, of which only the initial portion is shown in
the
drawing.
Cooperating with the spreading system 510 is a mechanism 525 to pick
up the tubular articles which are sucked inside the spreading system 510 and
which has the function of pulling each tubular article through the section of
passage defined by the inner wall of the end portion 513A of the compartment
513 and by the shutter element 515A described above.
The mechanism 525 is supported by a slide 527, movable according to
the double arrow f525 along a guide 529. Movement of the slide 527 is
controlled
by a belt 531 operated by a motor 533 and entrained around two pulleys. The
mechanism 525 is constrained to the slide 527 by means of a piston-cylinder
actuator 535 which controls the lifting and lowering niovement in a vertical
direction according to the double arrow f525X of the mechanism 525. The
lifting
and lowering movement of the mechanism 525 has the function of positioning
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said mechanism in line with the spreading system 510 and, alternatively, above
the latter. This facilitates and improves the efficiency of flattening of the
article
when it is made to pass through the shutter 515, as the article is pulled
against
the shutter element 515A.
The mechanism 525 comprises an approximately box-shaped
compartment 539, inside which a vacuum can be created by means of suction
through an aperture 541 which is connected with a tubular connector 543
through a suction box 543A. The tubular connector 543 can be connected to the
suction mouth 521 of the spreading system 510. This pneumatic connection is
achieved by moving mechanism 525 along with its connector 543 according to
the arrow f525 towards the suction mouth 521 and therefore towards the
spreading system 5101, to make the elements 510, 525 take the reciprocal
position shown in Figure 29. In this arrangement suction implemented through
the suction duct 523 causes suction through the box-shaped compartment 539,
the suction compartment 513 and the duct 7, 7B. Inside the box-shaped
compartment 539 is a grid 545 composed (Figure 26) of a series of teeth 545A
with a front edge (i.e. oriented towards the spreading system 510) inclined
with
respect to the horizontal. Associated with this grid formed by the teeth 545A
is a
retaining pawl 547 the movement of which according to the double arrow f547 is
controlled by a piston cylinder actuator 549 supported by the mechanism 525.
Combined with the grid 545 formed of the teeth 545A and of the pawl 547 is a
presser 551, provided with a vertical movement according to the double arrow
f551 controlled by a piston cylinder actuator 553. The presser 551 has a C-
shape
open towards the grid 545. The purpose thereof is to retain the tubular
article
during the spreading or flattening phase, acting thereon with a sufficiently
wide
surface to prevent the article from being damaged.
Operation of the spreading system and of the relative mechanism 525
described above will be explained later on with reference to the detailed
description of an operating cycle of the device.
In the station 509 is another spreading system 510X which has members
equivalent to those described with reference to the spreading system 510,
indicated in the figures with the same reference numbers followed by the
letter X.
The suction compartment 513X with rectangular section is connected to a
suction duct indicated with 8B and corresponding to the suction duct 7B. As
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opposed to a mechanism like the one indicated with 525, the spreading system
510X located in station 509 cooperates with a simple conveyor belt or mat 563
supported by a supporting structure 565 of the device and provided with a
movement according to f563 imparted by a motor 565. The conveyor belt 563 is
driven about rollers which are supported, together with the motor 565 and the
other members transmitting motion to the conveyor belt 563, by side panels 567
which move vertically by means of piston cylinder actuators 569, to allow the
conveyor belt 563 to move towards or away from the conveyor 503. The
conveyor belt 563 moves each individual article longitudinally, i.e. parallel
to the
extension thereof, in a transverse direction with respect to the direction of
feed F
of the conveyor belt 503 to take each tubular article inside the spreading
system
510X and remove it gradually therefrom when the shutter element, equivalent to
the shutter element 515A, is in the substantially closed position and suction
continues through the slot it leaves open.
Downstream of the second spreading station 509 (with respect to the
direction of feed F of the articles by conveyor 503) is a station 570 for
detecting
the ends of the tubular article. Located in this station is a presser 571,
provided
with a vertical lifting and lowering movement according to the double
arrow,f571
to press against the slats 503A forming the continuous conveyor 503, or to be
lifted therefrom. The lifting and lowering movement of the presser 571 is
controlled by an actuator 573 (Figure 30) supported by a slide 575 constrained
to
a belt 577. The belt 577 takes its motion from an actuator 579 and imparts an
alternate rectilinear horizontal movement, according to the double arrow f575,
to
the slide 575, to the actuator 573 and finally to the presser 571. The presser
571
is therefore provided with a double movement: vertical according to f571 and
horizontal according to f575 in a transverse direction with respect to the
direction
of feed F of the conveyor 503.
The presser 571 is positioned between two inclined profiles 581A, 581B
which extend transversely to the direction of feed F of the articles, i.e.
parallel to
the slats 503 of the conveyor 503. The profiles 581A, 581 B are supported by a
cross-member 583, in turn supported by piston-cylinder actuators 585
interposed
with the fixed structure 565. At the ends thereof, the cross member 583
supports
actuator and guide systems 587, to which the profiles 581A, 581B are
constrained, and which have the function of imparting a movement according to
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the double arrow f581 to the profiles 581A, 581B. In substance, the profiles
581A, 581B can be moved towards and away from each other. They have the
function of centering each individual article which is positioned between the
two
profiles 581A, 581B.
At the station 570, located on the side of the conveyor 503 is a detection
device which can comprise a camera, the images of which are processed by a
suitable image recognition software, or a series of photocells or other means
in
general suitable to recognize, i.e. to distinguish the two ends of each
tubular
article inserted in the device from each other. This detection system is
indicated
generically with 590 in the figure, and can be supported by a C-shaped
profile,
which holds, for example, a series of photoemitters and an opposed series of
photoreceivers, between which the end of each article closest to the sensor or
detection device 590 is inserted.
To carry the article with the end thereof under the detection elements the
previously described presser 571 is provided, and for this purpose it is
lowered to
press the article gently against the conveyor 503 and then, by translating
horizontally (arrow f575), to take it to the desired position. This is made
possible
by the low coefficient of friction with which the slats 503A forming the
conveyor
503 are produced.
In place of photocells, cameras or other optical reading systems, the
detection device 590 can also use other mechanisms. For example, the two ends
of each article could be made recognizable and distinguishable by inserting a
specific material in only one and not the other of the two ends. For example,
a
metal yarn, a magnetic thread or the like could be inserted in one of the two
ends
(preferably the toe to be sewn when the articles being handled are stockings
or
socks). Recognition of these threads can take place with a capacitive sensor,
a
magnetic sensor or other suitable mechanism.
In general, the present invention is not limited to the type of reading or
distinguishing mechanism to recognize and distinguish the two ends of each
article from each other. However, and preferably, optical systems capable of
recognizing and distinguishing the two ends on the basis of their geometricai
conformation are used, as with these systems it is possible to avoid using
special
materials during production of the articles and therefore the device according
to
the invention can be more generally used and the manufacturing costs of the
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articles are reduced, by avoiding the need to carry out special procedures in
the
production steps upstream.
As can be seen in particular in Figure 33, in a specific area the slats 503A
of the conveyor 503 have a series of holes 503C. In the drawing, these holes
are
indicated only for some of the slats 503A, to simplify representation, but it
must
be understood that in actual fact a band of perforations, slots or the like is
found
along the entire continuous extension of the conveyor 503. In other words,
each
of the slats 503A is provided with an open area through which the subsequent
reading operation can be performed to transversely position the article to
allow
subsequent handling in the station 600 to be described in detail hereunder.
More
specifically, each slat has suction holes and, at the two ends of the area
perforated for suction, two holes for corresponding photocells or other
optical
readers for positioning the tubular article, which are located under the
perforated
area 503C of the slats 503A. In place of optical readers, other suitable
sensor
means can be used.
With this arrangement, once the article has been taken under the sensors
or other detection members 590 and after the electronic control system of the
device 501 has checked whether the end positioned under the detection systems
590 is the first or second end, with a horizontal movement of the presser 571
in
one direction or the other, the article can be translated transversely with
respect
to the direction F of feed, to take the desired end to the apertures or slots
503C.
This is the position the article must be in, to be able to proceed, in the
subsequent station 600, with opening of the end of the article and
consequently
engage it by means of the engaging members of the station 600.
In practice, movement of the presser 571 is controlled so that the end of
the article to be subsequently engaged by the pick-up members is always
positioned on the apertures 503C. If the article to be handled is a sock,
which
must always be engaged at the elastic edge, movement of the presser 571 will
be controlled to take said elastic edge to the perforated area 503C. If the
elastic
edge is the end recognized by the detection system 590, the presser 571 will
move away from the detection system 590. Vice versa, if the end identified by
the detection system 590 is the toe, this means that the opposite end must be
taken to the perforated area 503C, and therefore the presser 571 will move in
the
opposite direction towards the detection system 590. If necessary, the presser
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571 can perform several repeated movements, lifting up from the article
between
one movement and the next to avoid moving it in the wrong direction. Once the
desired position has been reached with the end of the article over the
perforated
area 503C, suction can be activated to hold the article in position during the
subsequent forward movement of the conveyor 503.
The first member found in the station 600 is a stretching device 601
(Figure 33). The stretching device 601 is supported by a plate 603 rotating
about
a vertical axis X by means of a belt 605 controlled by a motor 607. The motor
607, and the support of the rotating plate 603, are supported by the fixed
structure 565 of the device. Located between the plates 603 and the stretching
device 601 is a piston-cylinder actuator 609 which provides said stretching
device with a lifting and lowering movement according to f601. This stretching
device cooperates with a suction system, not shown, located in the
intermediate
area between the upper branch and the lower branch of the conveyor 503, which
sucks through the apertures, slots or the like indicated with 503C. Each
individual article which is positioned with the end thereof at the stretching
device
601 can thus be opened by lowering the member 601, engaging a side of the
corresponding end of the article with this member 601, while the opposed side
of
material is held on the conveyor 503 by suction. The device 601 can be
oriented
about a vertical axis making it possible to also correctly handle "low cut"
socks.
Also fixed to the structure 565 in station 600 are the mechanisms and the
devices forming the two pick-up members which are activated alternatively
according to the orientation of the tubular article, to always engage the same
end
of the tubular article with one or other of said pick-up members. When this
is, for
example, a sock, the pick-up member which is correctly positioned to engage
the
elastic edge of said sock, forming the end previously stretched or opened by
the
stretching device 601, is activated. As the stretching device is disposed
between
the two pick-up members, it forms a common stretching device or member to
cooperate alternatively with one or with the other of the two pick-up members.
The opening of the edge will be oriented towards one or the other of the two
sides of the conveyor 503 according to the orientation with which the article
was
delivered from the suction duct 7 (toe or edge facing forward).
The mechanical elements which form the first and the second pick-up
member, and the relative actuators are shown in their movements in Figures 34
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to 42. where the other mechanical members of the device 501, not pertinent to
operation of the pick-up members, have been omitted.
In the station 600 a motor 611 is constrained to the fixed structure 565,
which motor by means of a belt 613 supplies the movement to a splined bar 615,
on which pulleys 617 are coupled. These pulleys are torsionally engaged with
the splined bar 615 but can slide longitudinally along the axis thereof. The
pulleys 617 supply the motion to respective belts 619, entrained around the
pulleys 617 and also around further idle pulleys 621. The pulleys 621 are
supported by slides 623 guided along a guide 624 integral with the load-
bearing
structure 565 and extending parallel to the splined bar 615.
The slides 623 can slide according to the double arrow f623. They are
also constrained by supports 625 to the drive pulleys 617 torsionally engaged
with the splined bar 615. Ultimately, therefore, the two beits 619 can move
towards and away from each other and also move independently from each
other according to the double arrow f623 in a direction orthogonal to the
direction
of feed F of the articles on the conveyor 503.
The movement of the individual slides 623 is controlled, independently for
each slide, by a piston-cylinder actuator 627. Each of the actuators 627 is
constrained to the load-bearing structure 565. Of these actuators, 627X
indicates
the rod which is rigidly constrained to the respective slide 623.
Reference number 631 indicates two pick-up members of the articles,
each of which is supported by a slide 633 sliding along a guide 635 rigidly
constrained to the corresponding slide 623. In substance, therefore, each of
the
slides 623 which translates orthogonally to the direction F of feed of the
articles
and of the conveyor 503, respectively. supports one of the two pick-up members
of the articles, each indicated with 631, movable parallel to the direction of
feed
F. Movement of the pick-up members 631 along the guides 635 is indicated in
the drawing with the double arrow f631.
Each pick-up member 631 has a pair of brackets 637, each of which
pivots about a respective horizontal axis 637A. A respective arm 639A, 639B is
integral with each bracket 637. The pivoting movement of the brackets 637 is
controlled by a piston-cylinder actuator 641 arranged in an intermediate
position
between two supporting side panels. Each of the arms 639A, 639B has, at the
lower end thereof, hinged about respective pivoting axes, respective fingers
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643A, 643B, The pivoting movement of the fingers 643A, 643B is controlled by a
respective piston-cylinder 645A, 645B.
The oscillating movement of the arms 639A, 639B, in combination with the
oscillating movements of the fingers 643A, 643B allows, as will be explained
hereunder, insertion of the fingers 643A, 643B of one pair into the open end
of a
tubular article and subsequent engaging by said fingers of the end of said
article.
The moving apart motion the fingers of each pair causes transverse stretching
of
the ends of the tubular article.
A bracket 651 supporting a piston-cylinder actuator 653 is rigidly
connected to each slide 633 supporting each pick-up member 631. The piston
cylinder actuator 653 controls the oscillating movement according to double
arrow f655 about a horizontal axis of a unit 655 which supports the tubular
article
engaged by one or other of the pick-up members 631. More specifically, the
unit
655 constrained to one slide 633 cooperates with the unit 631 constrained to
the
opposite slide 633, as will be more apparent from the description of a
complete
operating cycle of the device.
The unit 655 has at the end thereof a gripper member 657, the function of
which is to hold the tubular article in an intermediate area between the two
ends
to prevent it from interfering with other mechanical members when, by means of
the pick-up member 631 which engages the first end thereof, said article is
transferred e.g. to a pair of jaws 201 of subsequent manipulator members, for
example to insert each tubular article onto a transport tube or the like. The
jaws
201 are represented only schematically and separately from the rest in the
figures described herein, and can be substantially the same as and have the
same functions as the jaws 201 described with reference to Figures 1 to 20.
Having described the principal member of the device, the complete
operating cycle thereof will now be described with reference to the sequence
in
Figures 43A-43Q.
Figure 43A shows a schematic longitudinal section of the spreading system
and of the pick-up mechanism 525 when they are coupled to one another. The
tubular article M, such as a stocking or sock, is sucked by the duct 7 through
the
connector 7B inside the compartment 513 with rectangular section. Suction
takes
place through the tubular connector 543 and the suction box 543A and then
through the aperture 541 and the grid 545, as the connector 543 is connected
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with the suction mouth 521 and with the suction duct 523. Due to suction, the
article M moves forward according to the arrow fM until knocking against the
grid
545 (Figure 43B). Here it is engaged by the retaining tooth or pawl 547
(Figure
43B). In the example shown the article M has entered the suction duct 7 and
then the spreading system 510 with the elastic edge B facing forward and the
toe
P backward. This orientation is entirely random and depends on how the article
has been picked up from the container 1.
To spread the article M, at this point suction in the duct 7 is reversed and
the article is sucked into the duct again. If by error two articles enter the
compartment 513 simultaneously, one of them is unloaded back into the
container 1, as the retaining pawl 547 is dimensioned so that it is unable to
retain
two articles M. Figure 43C shows the article M extended towards the duct 7 but
held by the pawl 547. To perform flattening and spreading of the article M, at
this
point the shutter element 515A is taken to the closed position thereof, in
which it
defines a narrow and elongated section of passage. At the same time the
presser 551 is lowered for improved retention of the article M (Figure 43D).
The
retaining mechanism 525 is moved away (arrow f525, Figure 43E) pulling the
article M out of the constricted cross section defined by the shutter element
515A. In this phase suction can be activated through the duct 7 which
stretches
the article towards the inside of said duct. The effect of this operation is
to
spread the article not only longitudinally, but also, and above all,
transversely,
thanks to the narrow and elongated shape of the cross section of passage
defined by the shutter element 515A.
A similar process takes place for the opposite end (in this case the edge B)
of the article in the station 509, as schematically illustrated in Figure 43F,
after
the article has moved forward by one step according to the direction of the
arrow
F along the conveyor 503.
In the station 570 (Figure 43G) the tubular article M is engaged by the
presser 571, which for this purpose is lowered (Figures 43G-43H), and then
translated under the detection system 590 (Figure 431). The latter recognizes
which of the two ends is facing the detection system, the elastic edge B in
the
example shown. The object of the subsequent operations is to ultimately take
the
article M with the elastic edge B thereof inserted over the pair of jaws 201.
For
this purpose, in the first place this end (elastic edge B) must be positioned
at the
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level of the holes 503C, and this is again performed by the presser 571 which
moves from left to right (in the drawing) to take the position in Figure 43J).
The
profiles 581A, 581 B center the article correctly with respect to the suction
area
formed by the holes 503C, positioned under which is a suction mouth, indicated
schematically at 504 in Figures 43J-430. Suction starts in this phase, so that
subsequent feed from the station 570 to the station 600 takes place without
relative movements between the edge B of the article M and the conveyor 503.
In Figure 43K the article M is positioned with the edge B under the
stretching device 601, which is lowered to engage the side of the edge B
opposite the side which is held by suction on the conveyor 503. Subsequently,
(Figure 43L) the stretching device 601 is raised to stretch the edge and the
fingers 643A, 643B of one of the two pick-up members 631 are inserted into
said
edge. In the example shown the pick-up member 631 on the left (in the drawing)
is activated. If the article M had been oriented in the opposite direction,
the pick-
up member on the right (in the drawing) would have been activated due to the
different orientation of the opening of the edge B.
Figure 43M shows how the fingers 643A, 643B have been inserted in the
edge B and are subsequently (Figure 43N) respectively opened to horizontally
stretch the edge, which is released both by the suction holes 503C, and by the
stretching device 601.
To facilitate the subsequent operations of loading onto the jaw 201, the
article M is engaged in an intermediate point of the longitudinal extension
thereof
by the gripper member 657 which is on the right (in the drawing). If the
article M
had been oriented in the opposite direction, the opposed gripper member 657
215 would have been activated.
Finally, the fingers 643A, 643B are made to pivot from the horizontal
position to the vertical position (Figures 430-43P) and the pick-up member 631
supporting them is made to translate according to the arrow f631 (Figure 43Q)
to
position the edge B of the article M over the jaws 201. A subsequent lowering
movement allows the edge B to be inserted onto the jaws 201. Subsequent
handling operations can include loading onto a transport tube, as already
described with reference to the embodiment in Figures 1 to 20.
It is understood that the drawing only shows an example provided as a
practical embodiment of the invention, which may vary in forms and
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arrangements without however departing from the scope of the concept on which
the invention is based. Any reference numbers in the appended claimed are
provided to facilitate reading of the claims with reference to the description
and
to the drawing, and do not limit the scope of protection represented by the
claims.
